SPI is a manufacturer of precision measurement tools and instruments. Its product lines are designed for applications requiring accurate dimensional measurement, alignment, and leveling across various industrial and technical environments. The main product lines available through Centenary Materials include digital and dial gauges, vernier calipers, spirit levels, other measurement instrument series, and various new product releases. These tools provide the necessary precision for measuring lengths, diameters, and surface flatness. Centenary Materials offers in-stock supply, fast quotation and sourcing service for parts not currently listed.